APERTURE BLADE DRIVING DEVICE

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PROBLEM TO BE SOLVED : To provide a lens diaphragm driving device which can be made thinner than conventional ones and allows an effective turning range to be widened and can be mounted on an interchangeable lens. SOLUTION : A lens diaphragm driving device includes; a disk-like casing 2 having a fixing frame 21 and a hole seat 22; a plurality of diaphragm blades 3 provided in the casing 2; a driving wheel 4 which rotates each diaphragm blade around an optical axis; and a VCM 5 which directly drives the driving wheel 4. The VCM 5 includes : a pair of tabular yokes facing each other with a prescribed interval therebetween; tabular driving magnets 53a and 53b made of a rare earth sintered magnet, which are magnetized in a thickness direction and are fixed to at least one of the pair of tabular yokes; and a flat air core coil 54 supported so as to be movable relative to the driving magnets 53a and 53b within a plane orthogonal to the optical axis. The driving wheel 4 is driven so as to turn by 20° or more along a circumferential direction. COPYRIGHT : (C)2013, JPO&INPIT